How Rare Is Hypopituitarism

[Faith Lienhard]

Thepituitary gland is a small structure that is located just below the brain. It is attached by a stalk to the hypothalamus. The hypothalamus is the area of the brain that controls the pituitary gland's function.

In hypopituitarism, there is a lack of one or more pituitary hormones. Lack of a hormone leads to loss of function in the gland or organ the hormone controls. For example, lack of TSH leads to loss of normal function of the thyroid gland.

Certain medicines can also suppress pituitary function. The most common medicines are glucocorticoids (such as prednisone and dexamethasone), which are taken for inflammatory and immune conditions. Medicines used to treat prostate cancer can also lead to low pituitary function.

The level of a pituitary hormone may be high in the bloodstream if you have a pituitary tumor that is producing too much of that hormone. The tumor may compress other cells of the pituitary, leading to low levels of other hormones.

Always carry a medical ID (card, bracelet, or necklace) that says you have adrenal insufficiency. The ID should also say the type of medicine and dosage you need in case of an emergency caused by adrenal insufficiency.

Kaiser U, Ho K. Pituitary physiology and diagnostic evaluation. In: Melmed S, Auchus RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 8.

Updated by: Sandeep K. Dhaliwal, MD, board-certified in Diabetes, Endocrinology, and Metabolism, Springfield, VA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

The pituitary gland is a kidney-bean-sized gland at the base of your brain. It is part of the body's system of glands that make hormones, called the endocrine system. The pituitary gland makes several hormones. They act on nearly every part of the body.

The endocrine system is made up of glands and organs that make hormones. The endocrine system includes the pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreas, ovaries and testicles.

Hypopituitarism is when there isn't enough of one or more of the pituitary hormones. This lack of hormones, called a deficiency, can affect how the body works in many ways. These include growth, blood pressure and the ability to have children, among others. Symptoms depend on which hormones are missing.

Symptoms of hypopituitarism vary from person to person. Symptoms depend on what hormones are missing and how little of the hormone is being made. There might be more than one hormone that's low. A second hormone deficiency might increase the symptoms of the first one. Or sometimes, it might hide those symptoms.

Contact your health care provider right away if symptoms of hypopituitarism start suddenly or come with a bad headache, changes in vision, confusion or a drop in blood pressure. These could be symptoms of sudden damage to the pituitary gland tissue. This condition is known as pituitary apoplexy.

Hypopituitarism has a number of causes. One common cause is a tumor of the pituitary gland. As a pituitary tumor grows, it can press on and damage pituitary tissue. This disrupts the pituitary gland's ability to make hormones. A tumor also can press on the optic nerves, causing vision problems.

In some cases, a change in a gene causes hypopituitarism. That change is heredity, which means it is passed down in families. The genetic change affects the pituitary gland's ability to make one or more of its hormones. This often starts at birth or in early childhood.

Tumors or diseases of a part of the brain that's just above the pituitary, called the hypothalamus, also can cause hypopituitarism. The hypothalamus makes hormones that affect how the pituitary gland works.

Hypopituitarism is failure of the pituitary gland to produce one, some, or all of the hormones it normally produces. The pituitary gland has two parts, the anterior pituitary and the posterior pituitary, and hormone production can be affected in either or both parts.

Hypopituitarism can range from being asymptomatic to collapse and coma. The signs and symptoms of hypopituitarism depend on which part of the pituitary gland is involved, to what extent and for how long. It also depends on whether the hormone deficiencies began as a child or later in adult life. Symptoms can be slow at the start and vague. It is worth understanding the normal function and effects of these hormones in order to understand the signs and symptoms of hypopituitarism. (See the article on pituitary gland.) There may also be additional symptoms due to the underlying cause of the hypopituitarism, such as the effects of pressure from a tumour.

Hypopituitarism is rare. At any given time, between 300 and 455 people in a million may have hypopituitarism. Hypopituitarism is more common after special situations e.g. brain injuries and postpartum haemorrhage.

If it is suspected that there is a lack of anti-diuretic hormone (as can be the case with Diabetes Insipidus), the doctor may organise a water deprivation test. The patient will be deprived of water for a period of eight hours under very close supervision with regular blood, urine tests and body weight. The test may be extended up to a 24 hour period if needed, which means an overnight stay in hospital.

Other tests may also be organised to try and identify the underlying cause of the hypopituitarism. These could include blood tests, scans such as computerised tomography (CT) or magnetic resonance imaging (MRI) scans, and tests for vision.

People with hypopituitarism may have an impaired quality of life. Hypopituitarism is associated with an increased risk of heart disease and strokes as a result of the physical changes that occur in body fat, cholesterol and circulation. Healthy living, smoking cessation, a balanced diet and exercise are essential to reduce this risk.

People with hypopituitarism also have a higher risk of developing osteoporosis or brittle bones and, therefore, have a higher risk of developing fractures from minor injuries. A diet that is rich in calcium and vitamin D along with moderate amounts of weight-bearing exercise and training are helpful in decreasing this risk.

Symptoms are different for each person. They may happen over time or right away. They depend on which hormones the pituitary gland is not making enough of. These hormone deficiencies, and the symptoms they cause, include:

Not enough gonadotropins (luteinizing hormone and follicle-stimulating hormone). This affects men and women who have not gone through menopause. Women may not have a menstrual period. They may have problems with fertility, vaginal dryness, and loss of some female traits. Men may have problems with fertility, sexual function, and loss of some male traits. Children will not go through puberty.

Not enough thyroid-stimulating hormone. This often leads to an underactive thyroid. It may cause lack of energy (fatigue), confusion, problems with cold temperatures, weight gain, constipation, and dry skin.

Not enough ACTH (adrenocorticotropin hormone). This is rare. Your pituitary gland may not secrete ACTH if you have been taking adrenal steroid hormones and stop taking them suddenly. It leads to an underactive adrenal gland. You may have low blood pressure, low blood sugar, feel tired, and be easily stressed.

Tumor metastasis to the pituitary gland is a rare, not well-documented and life-threatening condition associated with a shortened life span. A better understanding of its clinical manifestations could lead to earlier diagnosis, appropriate therapy and potentially improving quality of life. Therefore, we retrospectively studied the charts of patients with pituitary metastases who were treated at the City of Hope National Medical Center (Duarte, CA) from 1984 to 2018. We reviewed and analyzed tumor origin, primary pituitary clinical manifestation, duration between primary tumor diagnosis and pituitary metastasis, type of treatment and patient survival. A total of 11 patients were identified with a mean age of 59.2 years and median survival following the diagnosis of metastasis of 10 months. Breast cancer and lymphoma were the most common primary origins in these cases, and diabetes insipidus and panhypopituitarism were the most common clinical manifestations of their metastasis. We also compared our results with reports in the literature published between 1957 and 2018. A total 289 patients with pituitary metastasis have been reported in the literature. Breast cancer was the most frequent primary origin of the metastasis, and visual symptoms were the most common primary manifestation. The posterior part of the pituitary is more susceptible than the anterior to metastasis. Pituitary metastasis may occur as a consequence of successful primary tumor treatment prolonging the chance of seeding. Future studies are needed to determine the molecular mechanism of metastasis to the pituitary.

3a8082e126